Evaluation of cumulative fatigue lives under different biaxial loading mode sequences for notched specimens

Results of Two-level cumulative fatigue tests under different biaxial loading mode sequence for notched specimens are analyzed in this paper. Several approaches such as Miner's rule, a damage curve approach and a double linear damage rule were used to evaluate forty-eight cumulative fatigue tests. It is found that Miner's rule, where damage is expressed as a function of residual tensile strength and double linear damage rule, can predict most cycle ratios at the second level within +/-0.3 deviation bands. Comparison is made between these predictions. Finally the relation between crack behavior and the complex loading mode sequence is also discussed to explain the results.